[I've used a 5 stage RO/DI from h2ofix.com for the past 8 months. I figured it would be nice to know what was coming out of the unit at this point, and Hanna makes an instrument that tests "TDS"... don't ask me what it stands for, but if it tests 000, you've got pure water.
My tap water reads TDS at 277.
After my RO membrane, the water is 6.
After the DI cartridge, the water is 0 (or 000 tecnically).
When the numbers start going up, I'll know it is time to change the DI cartridge. Another indicator is the cartridge changes colors, from black to brown. Right now, the bottom third of mine is brown, so I'm guessing it won't need changing until the end of summer or even this winter perhaps.
Some RO/DI units come with a TDS meter, with numbers or sometimes with a simple green light/red light system. Regardless, it is good to know if you water is pure, or if it needs to have the filters exchanged.
I found out that a good way to know if your carbon filters need replacing is to check for clorine. If you detect none, the carbon filters are still good.
Also, some 5-stage systems use two DI cartridges. I asked about that, because it doesn't make a lot of sense to me. If your DI pulls out the last of the impurities, giving you a reading of 000, then why would you need another one behind it? Wouldn't the extra be redundant and basically useless? "Yes" is the answer I got. If your water is pure, you don't need another DI. What is more pure than pure?
I also wanted to know about "flush kits", where you reverse the flow through your RO membrane to extend the life of the RO. A number of people swear by this, saying it is the only way to go. Well, it seems to be more of a sales feature than an actual benefit, according to Mark at h2ofix.com. RO membranes should last you 5 years without needing to be fiddled with. He's got some that have lasted 10 years and continue to work just fine.
Hopefully you found this information useful. I know I did. ::]
My tap water reads TDS at 277.
After my RO membrane, the water is 6.
After the DI cartridge, the water is 0 (or 000 tecnically).
When the numbers start going up, I'll know it is time to change the DI cartridge. Another indicator is the cartridge changes colors, from black to brown. Right now, the bottom third of mine is brown, so I'm guessing it won't need changing until the end of summer or even this winter perhaps.
Some RO/DI units come with a TDS meter, with numbers or sometimes with a simple green light/red light system. Regardless, it is good to know if you water is pure, or if it needs to have the filters exchanged.
I found out that a good way to know if your carbon filters need replacing is to check for clorine. If you detect none, the carbon filters are still good.
Also, some 5-stage systems use two DI cartridges. I asked about that, because it doesn't make a lot of sense to me. If your DI pulls out the last of the impurities, giving you a reading of 000, then why would you need another one behind it? Wouldn't the extra be redundant and basically useless? "Yes" is the answer I got. If your water is pure, you don't need another DI. What is more pure than pure?
I also wanted to know about "flush kits", where you reverse the flow through your RO membrane to extend the life of the RO. A number of people swear by this, saying it is the only way to go. Well, it seems to be more of a sales feature than an actual benefit, according to Mark at h2ofix.com. RO membranes should last you 5 years without needing to be fiddled with. He's got some that have lasted 10 years and continue to work just fine.
Hopefully you found this information useful. I know I did. :
:]